Hydraulic coupling device and male and female coupling units

ABSTRACT

A female coupling unit for a hydraulic coupling device, comprises a female coupling body comprising a hollow core, wherein a rear sealing ring is provided along an inner circumferential surface of a sealing sleeve device and adapted to bear against and slide along a front end portion of a female poppet device during movement of the sealing sleeve device, wherein the rear sealing ring is configured to prevent flow of hydraulic fluid between the rear sealing ring and the female poppet device from the rear end of the female coupling body towards the front end of the female coupling body and enable flow of hydraulic fluid between the rear sealing ring and the female poppet device from the front end of the female coupling body towards the rear end of the female coupling body.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a § 371 national stage entry of InternationalApplication No. PCT/SE2018/050899, filed Sep. 7, 2018, which claimspriority of Sweden National Application No. 1751092-6, filed Sep. 8,2017, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates generally to a hydraulic coupling deviceand male and female coupling units for a hydraulic coupling device.

BACKGROUND ART

It is known to use hydraulic coupling devices for enabling the quickconnection between working machines and a variation of hydraulicallyoperated tools. Generally, hydraulic coupling devices comprises a femalecoupling unit and male coupling unit adapted to matingly engage witheach other. One coupling unit, usually the female coupling unit, isarranged to the working machine via a holding block. The male couplingunit is usually arranged in a tool. The respective coupling units areadapted to provide a seal against leakage of hydraulic fluid duringnon-use, i.e. when not connected to each other, by the aid of valvedevices. Upon connection, the valves are opened and hydraulic fluid isallowed to flow between the working machine and the hydraulicallyoperated tool. Further, the valve device comprises a fixedly mountedpart and a poppet device movable in relation to the fixedly mounted partwith a spring connecting the poppet device and the fixedly mounted part.The fixedly mounted part is arranged to the inner part of the malecoupling unit via circlip.

A drawback of known solutions is that the valve device of the malecoupling unit comprises multiple parts which are cumbersome andtime-consuming to assemble. The guidance between the poppet device andthe fixedly mounted part is poor and solely enabled via a guide pin,whereby the poppet device may be tilted in relation to the fixedlymounted part. A further drawback is thus that, as a result, the circlipmay be brought out of its position, whereby all valve device parts arereleased and either become stuck in the male coupling unit causingmalfunction of the valve device and leakage of hydraulic oil duringnon-use, or moves into the hydraulic flow causing malfunction of thetool. Alternatively, during tilting, the poppet device become stuck inthe male coupling unit with similar negative results as above.

Yet another drawback of known solutions is that the sealing rings usedin the female and male coupling units, so-called o-rings, provideunsufficient sealing capacity, as well as require additional means andassembly steps for fixation as their flexibility otherwise may cause theo-rings to release undesirably from their position causing leakage andmalfunction of the tools as they enter the hydraulic flow.

SUMMARY OF INVENTION

An object of the present invention is to alleviate some of thedisadvantages of the prior art and to provide a hydraulic couplingdevice which requires less parts and is easier to assemble. A furtherobject of the present invention is to provide a hydraulic couplingdevice that reduces risk of malfunction of the device or thehydraulically operated tools connected thereto, hence provide a morereliable hydraulic coupling device.

According to one embodiment of the invention, a male coupling unit for ahydraulic coupling device is provided, comprising a male coupling bodycomprising a hollow core comprising a male coupling body center axisextending in a male coupling body extension direction, wherein the malecoupling body comprises an inner surface wherein the male coupling bodyfurther comprising a poppet valve device arranged in the hollow core,wherein the poppet valve device comprises a poppet device, a guidedevice, and a spring device, wherein a first end of the spring device issupported by the poppet device and a second end of the spring device issupported by the guide device, wherein the poppet device is movable inrelation to the guide device along the male coupling body extensiondirection between an open and closed position upon compression andextension of the spring device respectively, wherein the guide device islocked in the male coupling body extension direction, wherein the innersurface comprises a thread surface portion, wherein the guide devicecomprises an outer surface comprising a thread surface portionconfigured to engage with the corresponding thread surface portion ofthe inner surface of the male coupling body for locking the guideportion.

According to one embodiment, the guide device comprises a center portionextending in the male coupling body extension direction and a pluralityof legs extending in a direction from the first extension directiontowards the thread surface portion, forming lead-through channelsbetween the legs, wherein the thread surface portion is formed on theouter ends of the legs.

According to one embodiment, the guide device comprises three legs.

According to one embodiment, the poppet device comprises a cylindricalhollow core comprising the first end of the spring device, wherein theguide device comprises a cylindrical hollow core comprising the secondend of the spring device, wherein the poppet device and guide device areconfigured to matingly engage each other wherein the spring device isentirely enclosed within the poppet device and the guide device.

According to one embodiment, a male coupling unit for a hydrauliccoupling device is provided, comprising a male coupling body comprisinga hollow core comprising a male coupling body center axis extending in amale coupling body extension direction, wherein the male coupling bodycomprises an inner surface wherein the male coupling body furthercomprising a poppet valve device arranged in the hollow core; whereinthe poppet valve device comprises a poppet device, a guide device, and aspring device, wherein a first end of the spring device is supported bythe poppet device and a second end of the spring device is supported bythe guide device, wherein the poppet device is movable in relation tothe guide device along the male coupling body extension directionbetween an open and closed position upon compression and extension ofthe spring device respectively, wherein the guide device is locked inthe male coupling body extension direction, wherein the inner surfacecomprises a thread surface portion, wherein the poppet device comprisesa cylindrical hollow core comprising the first end of the spring device,wherein the guide device comprises a cylindrical hollow core comprisingthe second end of the spring device, wherein the poppet device and guidedevice are configured to matingly engage each other wherein the springdevice is entirely enclosed within the poppet device and the guidedevice.

According to one embodiment, the guide device comprises a cylinderportion, wherein the inner diameter of the cylindrical hollow core ofthe poppet device is larger than the outer diameter of the cylinderportion of the guide portion, wherein the poppet device and guide devicematingly engage each other by the guide device being partly insertedinto the cylindrical hollow core of the poppet device.

According to one embodiment, the spring device comprises at least onespring.

According to one embodiment, the spring device comprises a plurality ofsprings.

According to one embodiment, a poppet sealing ring is provided in acircumferential groove of the poppet device.

According to one embodiment, the poppet sealing ring comprises acircumferential groove.

According to one embodiment, the poppet sealing ring is made ofpolyurethane.

According to one embodiment, a female coupling unit for a hydrauliccoupling device is provided, comprising a female coupling bodycomprising a hollow core, wherein the female coupling body comprising arear end and a front end, a sealing sleeve device, wherein the sealingsleeve device is supported by a spring device and movable in relation tothe female coupling body between a closed and open position uponextension and compression of the spring device respectively, furthercomprising a female poppet device fixedly arranged to the rear end ofthe female coupling body in the hollow core and extending towards thefront end of the female coupling body; wherein a rear sealing ring isprovided along an inner circumferential surface of the sealing sleevedevice and adapted to bear against and slide along a front end portionof the female poppet device during movement of the sealing sleevedevice, wherein the rear sealing ring is configured to prevent flow ofhydraulic fluid between the rear sealing ring and the female poppetdevice from a rear end of the female coupling body towards a front endof the female coupling body and enable flow of hydraulic fluid betweenthe rear sealing ring and the female poppet device from a front end ofthe female coupling body towards a rear end of the female coupling body.

According to one embodiment, the rear sealing ring comprises an innerdiameter, wherein the inner diameter is variable.

According to one embodiment, the rear sealing ring comprises acircumferential groove facing the rear end of the female coupling body,wherein the circumferential groove is configured to provide elasticityand enable the variation of the inner diameter.

According to one embodiment, a front sealing ring is provided along aninner circumferential surface of the sealing sleeve device at a frontend of the sealing sleeve device, wherein the front sealing ringcomprises an inner diameter, wherein the inner diameter is variable.

According to one embodiment, the front sealing ring comprises acircumferential groove facing the rear end of the female coupling body,wherein the circumferential groove is configured to provide elasticityand enable the variation of the inner diameter.

According to one embodiment, the rear sealing ring is made ofpolyurethane.

According to one embodiment, the front sealing ring is made ofpolyurethane.

According to one embodiment, a hydraulic coupling device is providedcomprising a male coupling unit according to any of the embodimentsdescribed above, and a female coupling unit according to any of theembodiments described above.

According to one embodiment, the hydraulic coupling device, furthercomprises a holding block, a guiding ring, an expanding ring for fixedlyarranging the female coupling unit to the holding block in an opening ofthe holding block, wherein the guiding ring comprises an outer surfacecomprising a thread surface portion configured to engage with a threadsurface portion of a cylindrical portion of an opening of the holdingblock fixedly arranging the guiding ring to the holding block, wherein aseat is provided in the opening of the holding block for supporting theexpanding ring, wherein an outer surface of the front end portion of thefemale coupling body comprises a circumferential groove comprising agroove seat, configured to receive the expanding ring, wherein thefemale coupling unit is adapted to be fixedly arranged to the holdingblock by being suspended between the guiding ring and the seat, whereinthe expanding ring is arranged as a support between the female couplingunit and the seat.

According to one embodiment, a hydraulic coupling device is providedcomprising a male coupling unit, a female coupling unit, a holdingblock, a guiding ring, and an expanding ring for fixedly arranging thefemale coupling unit to the holding blockin an opening of the holdingblock, wherein the guiding ring comprises an outer surface comprising athread surface portion configured to engage with a thread surfaceportion of the cylindrical portion of the opening of the holding blockfixedly arranging the guiding ring to the holding block, wherein a seatis provided in the opening for supporting the expanding ring, wherein anouter surface of the front end of the female coupling body comprises acircumferential groove comprising a groove seat, configured to receivethe expanding ring, wherein female coupling unit is adapted to befixedly arranged to the holding block by being suspended between theguiding ring and the seat, wherein the expanding ring is arranged as asupport between the female coupling unit and the seat.

According to one embodiment, the hydraulic coupling device furthercomprises a male coupling unit as described in the embodiments above.

BRIEF DESCRIPTION OF DRAWINGS

The invention is now described, by way of example, with reference to theaccompanying drawings, in which:

FIG. 1 shows a perspective view of a working machine with a quickcoupler and a hydraulic coupling device for attaching and connecting ahydraulically operated tool thereto.

FIG. 2 shows an enlarged view of the quick coupler and the hydrauliccoupling device according to the invention according to FIG. 1 .

FIG. 3 a shows a perspective front end view of a male coupling unit of ahydraulic coupling device according to one embodiment of the inventionand according to FIG. 1-2 .

FIG. 3 b shows a perspective rear end view of a male coupling unit of ahydraulic coupling device according to FIG. 3 a.

FIG. 3 c shows a front end side view of a male coupling unit of ahydraulic coupling device according to FIG. 3 a.

FIG. 3 d shows a rear end side view of a male coupling unit of ahydraulic coupling device according to FIG. 3 a.

FIG. 3 e shows a side view of a male coupling unit of a hydrauliccoupling device according to FIG. 3 a.

FIG. 3 f shows a cross-section view of a male coupling unit along lineA-A of FIG. 3 e.

FIG. 4 a shows a perspective front end view of a female coupling unit ofa hydraulic coupling device according to one embodiment of theinvention.

FIG. 4 b shows a perspective rear end view of a female coupling unit ofa hydraulic coupling device according to FIG. 4 a.

FIG. 4 c shows a front end side view of a female coupling unit of ahydraulic coupling device according to FIG. 4 a.

FIG. 4 d shows a rear end side view of a female coupling unit of ahydraulic coupling device according to FIG. 4 a.

FIG. 4 e shows a side view of a male coupling unit of a hydrauliccoupling device according to FIG. 3 a.

FIG. 4 f shows a cross-section view of a male coupling unit along lineA-A of FIG. 4 e.

FIG. 5 a shows a cross-section side view of a hydraulic coupling devicein a closed position.

FIG. 5 b shows a cross-section side view of a hydraulic coupling devicein an open position.

DESCRIPTION OF EMBODIMENTS

In the following, a detailed description of the invention will be given.In the drawing figures, like reference numerals designate identical orcorresponding elements throughout the several figures. It will beappreciated that these figures are for illustration only and are not inany way restricting the scope of the invention.

FIG. 1 shows a perspective view of a working machine 1 with a quickcoupler 5 and a hydraulic coupling device 10 according to one embodimentof the invention, for attaching and connecting a hydraulically operatedtool thereto.

FIG. 2 shows an enlarged view of the quick coupler 5 and the hydrauliccoupling device 10 connected to a holding block 50. According to oneembodiment, the holding block 50 is arranged to the quick coupler 2.According to one embodiment, the holding block 50 is arranged to thequick coupler 5 via linear controls. According to one embodiment theholding block 50 is arranged to the quick coupler 2 via hydrauliccylinders. According to one embodiment, the holding block 50 is movablein relation to the quick coupler 5 during connection of the male 20 andfemale 30 coupling units of the hydraulic coupling device 10. As seen inFIG. 2 , a female coupling unit 30 of the hydraulic coupling device 10is arranged to the holding block by the aid of an expanding ring 60. Anhydraulically operated tool (not shown) equipped with a male couplingunit 20 may then be attached to the quick coupler 5 and the male andfemale coupling units are brought into mating engagement with eachother.

FIG. 3 a shows a perspective front end view of a male coupling unit 20of a hydraulic coupling device 10. The hydraulic coupling unit 20comprises a male coupling body 21 further comprising an outer surface 21a. At the front end of the male coupling body poppet device 24 isarranged.

FIG. 3 b shows a perspective rear end view of a male coupling unit 20 ofa hydraulic coupling device 10. The male coupling unit 20 comprises amale coupling body 21, comprising a hollow core 21 c and an innersurface 21 b. The inner surface portion comprises a thread surfaceportion 21 b 1.

FIG. 3 c shows a front end side view of a male coupling unit 20 of ahydraulic coupling device 10.

FIG. 3 d shows a rear end side view of a male coupling unit 20 of ahydraulic coupling device 10. A guide device 25 is disclosed comprisinga center portion and a plurality of radial legs 25 d 1, 25 d 2, 25 d 3providing a lead-through for the hydraulic fluid.

FIG. 3 e shows a side view of a male coupling unit 20 of a hydrauliccoupling device 10.

FIG. 3 f shows a cross-section view of a male coupling unit 20 of ahydraulic coupling device 10 along line A-A of FIG. 3 e . According toone embodiment, the hydraulic coupling device 10 comprises a malecoupling unit 20, further comprising a male coupling body 21 comprisinga hollow core 21 c comprising a male coupling body center axis 21′extending in a male coupling body extension direction. According to oneembodiment, the male coupling body extension direction is thus directedin both directions of the male coupling body center axis 21′. The malecoupling body 21 comprises an outer surface 21 a and an inner surface 21b. According to one embodiment, the male coupling body 21 comprises apoppet valve device 23 configured to seal the outside from the interiorof the male coupling body 21 through opening 21 f of the male couplingbody 21 in a closed position, and open the outside from the interior ofthe male coupling body 21 through the opening 21 f in an open position.The poppet valve device 23 comprises poppet device 24, a guide device 25and a spring device 26, wherein a first end 26 a of the spring device 26is supported by the poppet device 24, wherein a second end 26 b of thespring device 26 is supported by the guide device 25, wherein the poppetdevice 24 is movable in relation to the guide device 25 along the malecoupling body extension direction between an open and closed positionupon compression and extension of the spring device 26 respectively,wherein the guide device 25 is locked in the male coupling bodyextension direction, wherein the inner surface 21 b of the male couplingbody 21 comprises a thread surface portion 21 b 1, wherein the guidedevice 25 comprises an outer surface 25 a comprising a thread surfaceportion 25 a 1 configured to engage with the corresponding threadsurface portion 21 b 1 of the inner surface 21 b of the male couplingbody 21 for locking the guide device 25. According to one embodiment,the thread surface portion 25 a 1 is configured to engage with thecorresponding thread surface portion 21 b 1 of the inner surface 21 b ofthe male coupling body 21 for locking the guide device 25 in a malecoupling body extension direction. According to one embodiment,extension of the of spring device 26 comprises a relative movement froma compressed spring device 26 towards a relatively more extended springdevice 26.

According to one embodiment, the poppet valve device 23 comprises apoppet sealing ring 28 provided in a circumferential groove 24 d of thepoppet device 24. FIG. 3 f further discloses an enlarged view of thepoppet sealing ring 28. According to one embodiment, the poppet sealingring 28 comprises a circumferential groove 28 a. According to oneembodiment, the poppet sealing ring 28 comprises an outer diameter,wherein the outer diameter is variable. According to one embodiment, thepoppet sealing ring 28 comprises a circumferential groove 28 a facingthe rear end portion 21 d of the male coupling body 21, wherein thecircumferential groove 28 a is configured to provide elasticity andenable the variation of the outer diameter as well as providing achannel for hydraulic fluid which when filled with pressurized hydraulicfluid increases the outer diameter. According to one embodiment, theeffect of an increased outer diameter corresponds to an increasingsealing force against a surface abutting or bearing against the poppetsealing ring 28, such as the inner surface 21 b at the opening 21 f ofthe male coupling body 21 in a closed position. According to oneembodiment, the circumferential groove 28 a is v-shaped. According toone embodiment, the poppet sealing ring 28 is configured to abut or bearagainst the male coupling body 21 with a higher force upon an increasingpressure of a hydraulic fluid within the male coupling body 21.According to one embodiment, the outer diameter is defined by awedge-shaped portion 28 b. According to one embodiment, the wedge-shapedportion 28 b is shaped to provide a faster increase of the outerdiameter in a direction from the rear end portion 21 d to the front endportion 21 e of the male coupling body 21 compared to a direction fromthe front end portion 21 e to the rear end portion 21 d of the malecoupling body 21.

According to one embodiment, the poppet sealing ring 28 is made ofpolyurethane, also known as PUR.

According to one embodiment, the poppet valve device 23 is biasedtowards a closed position by the spring device 26. According to oneembodiment, the guide device 25 comprises a center portion 25 eextending in the male coupling body extension direction and a pluralityof radial legs 25 d 1, 25 d 2, 25 d 3 extending in a direction from themale coupling body center axis 21′ towards the thread surface portion 21b 1. According to one embodiment, the radial legs 25 d 1, 25 d 2, 25 d 3provides a lead-through for the hydraulic fluid between a front end 21 eand a rear end 21 d of the male coupling body 21. According to oneembodiment, the radial legs 25 d 1, 25 d 2, 25 d 3 provides alead-through for the hydraulic fluid between a front end 21 e and a rearend 21 d of the male coupling body 21 between the radial legs 25 d 1, 25d 2, 25 d 3. According to one embodiment, the guide device 25 comprisesthree legs 25 d 1, 25 d 2, 25 d 3. As seen in FIG. 3 d , according toone embodiment, the three legs 25 d 1, 25 d 2, 25 d 3 extend from themale coupling body center axis 21′ with an interval of 120°. As seen inFIG. 3 d , according to one embodiment, the three legs 25 d 1, 25 d 2,25 d 3 extend from the male coupling body center axis 21′ and areseparated from each other by an angular distance of 120°. According toone embodiment, the plurality of radial legs 25 d 1, 25 d 2, 25 d 3, . .. , 25 dn extend in a direction from the male coupling body center axis21′ towards the thread surface portion 21 b 1 and are separated fromeach other with an angular distance evenly distributed between theplurality of radial legs 25 d 1, 25 d 2, 25 d 3, 25 dn. Thus, e.g. inthe example of four radial legs, the radial legs are separated from eachother with an angular distance of 90°. According to one embodiment, theplurality of radial legs 25 d 1, 25 d 2, 25 d 3, . . . , 25 dn extend ina direction from the male coupling body center axis 21′ towards thethread surface portion 21 b 1 and are separated from each other with anangular distance. According to one embodiment, the angular distance isunevenly distributed between the plurality of radial legs 25 d 1, 25 d2, 25 d 3, . . . , 25 dn.

According to one embodiment, the poppet device 24 comprises acylindrical hollow core 24 c, and outer surface 24 a and an innersurface 24 b. According to on embodiment, the cylindrical hollow core 24c of the poppet device 24 comprises the first end 26 a of the springdevice 26. According to one embodiment, the poppet device 24 forms astop portion 24 b 2 of the inner surface 24 b configured to support thefirst end 26 a of the spring device 26. According to one embodiment, theguide device 25 comprises a cylindrical hollow core 25 c, an outersurface 25 a and an inner surface 25 b. According to one embodiment, thecylindrical hollow core 25 c of the guide device 25 comprises the secondend 26 b. According to one embodiment, the guide device 25 forms a stopportion 25 b 2 of the inner surface 25 b configured to support thesecond end 26 b of the spring device 26. According to one embodiment,the poppet device 24 and the guide device 25 matingly engage each otherwherein the spring device 26 is entirely enclosed within the poppetdevice 24 and the guide device 25. According to one embodiment, thespring device 26 is entirely enclosed within the poppet valve device 23.According to one embodiment, center portion 25 e of the guide device 25comprises a cylinder portion 25 e. According to one embodiment, an innerdiameter of the cylindrical hollow core 24 c of the poppet device 24 islarger than the outer diameter of the cylinder portion of the guidedevice 25, wherein the poppet device 24 and guide device 25 matinglyengage each other by the poppet device 24 encompassing the guide portion25. According to one embodiment, the poppet device 24 and guide device25 matingly engage each other by a portion of the poppet device 24overlaps a portion of the guide portion 25. According to one embodiment,the poppet device 24 and guide device 25 matingly engage each other bythe guide device 25 being partly inserted into the cylindrical hollowcore 24 c of the poppet device 24. According to one embodiment, thespring device 26 comprises at least one spring 26 c 1. According to oneembodiment, the spring device 26 comprises a plurality of springs 26 c1, 26 c 2, i.e. at least two springs but comprising any number ofsprings. According to one embodiment, the plurality of springs 26 c 1,26 c 2 enables the selection of a desired spring force for generating asufficient closing force of the male coupling unit 20 for specificpurposes preventing leakage of hydraulic fluid.

FIG. 4 a shows a perspective front end view of a female coupling unit 30of a hydraulic coupling device 10. The hydraulic coupling unit 30comprises a female coupling body 31 further comprising an outer surface31 a. At the front end 31 e of the female coupling body 3, a femalepoppet device 33 is shown.

FIG. 4 b shows a perspective rear end view of a female coupling unit 30of a hydraulic coupling device 10. The female coupling unit 30 comprisesa female coupling body 31, comprising a hollow core 31 c and an innersurface 31 b.

FIG. 4 c shows a front end side view of a female coupling unit 30 of ahydraulic coupling device 10.

FIG. 4 d shows a rear end side view of a female coupling unit 30 of ahydraulic coupling device 10. According to one embodiment, the rear endportion 31 d comprises a plurality of orifices 35 d 1, 35 d 2, 35 d 3,35 d 4 providing lead-throughs for the hydraulic fluid.

FIG. 4 e shows a side view of a female coupling unit 30 of a hydrauliccoupling device 10.

FIG. 4 f shows a cross-section view of a female coupling unit along lineA-A of FIG. 4 e . FIG. 4 f further discloses enlarged views of a rearsealing ring 34 and a front sealing ring 35. According to oneembodiment, the female coupling unit 30 further comprising a femalecoupling housing 31 comprising a rear end portion 31 d and a front endportion 31 e, a sealing sleeve device 32, wherein the sealing sleevedevice 32 is supported by a spring device 36 and movable in relation tothe female coupling housing 31 between a closed and open position uponextension and compression of the spring device 36 respectively.According to one embodiment, extension of the of spring device 36comprises a relative movement from a compressed spring device 36 towardsa relatively more extended spring device 36. According to oneembodiment, a rear end portion 31 d comprising a female poppet device 33extending along a female coupling body center axis 31′ of the femalecoupling body 31 towards the front end 31 e of the female coupling body31, wherein a rear sealing ring 34 is provided along an innercircumferential surface 32 b of the sealing sleeve device 32 and adaptedto abut or bear against and slide along a front end portion of thefemale poppet device 33 during movement of the sealing sleeve device 32,wherein the rear sealing ring 34 is configured to prevent flow ofhydraulic fluid between the rear sealing ring 34 and the female poppetdevice 33 from a rear end 31 d of the female coupling housing 31 towardsa front end 31 e of the female coupling housing 31 and enable flow ofhydraulic fluid between the rear sealing ring 34 and the female poppetdevice 33 from a front end 31 e of the female coupling housing towards arear end 31 d of the female coupling housing. According to oneembodiment, a desired effect of this is feature is that it enables highpressure of the hydraulic fluid in the male coupling body 21, i.e. in ahydraulically operated work tool connected to the male coupling body tobe reduced in a controlled manner by allowing hydraulic fluid to enterthe female coupling body 31 during connection of the male 21 and female31 coupling body. According to one embodiment, the rear sealing ring 34functions as a check valve or as a safety valve. The alternative, aspresent in the background art, is that rear sealing rings consists ofo-rings which essentially provides an equal sealing capability in bothdirections whereby the pressure of the hydraulic fluid in the malecoupling body 21 may force the o-ring out of position to eventuallyenter the hydraulic fluid, causing malfunction of the hydraulic couplingdevice and/or the hydraulically operated work tool. According to oneembodiment, the rear sealing ring 34 is held in place in the innercircumferential surface 32 b by a seat 32 f of the sealing sleeve device32 and a locking ring 37. According to one embodiment, the sealingsleeve device 32 comprising the rear sealing ring 34 and the femalepoppet device 33 are configured to engage so that during a closedposition, the outside is sealed from the interior of the female couplingbody 31 through an opening 31 f, and during an open position, theoutside is open from the interior of the female coupling body 31 throughthe opening 31 f.

According to one embodiment, the rear sealing ring 34 comprises an innerdiameter, wherein the inner diameter is variable. According to oneembodiment, the rear sealing ring 34 comprises a circumferential groove34 a facing the rear end portion 31 d of the female coupling body 31,wherein the circumferential groove 34 a is configured to provideelasticity and enable the variation of the inner diameter as well asproviding a channel for hydraulic fluid which when filled withpressurized hydraulic fluid reduces the inner diameter. According to oneembodiment, the effect of a reduced inner diameter corresponds to anincreasing sealing force against a surface abutting or bearing againstthe rear sealing ring 34, such as the female poppet device 33 in aclosed position. According to one embodiment, the circumferential groove34 a is v-shaped. According to one embodiment, the rear sealing ring 36is configured to bear against the female poppet device 33 with a higherforce upon an increasing pressure of an hydraulic fluid within thefemale coupling housing 31. According to one embodiment, the innerdiameter is defined by a wedge-shaped portion 34 b. According to oneembodiment, the wedge-shaped portion 34 b is shaped to provide a fasterreduction of the inner diameter in a direction from the rear end portion31 d to the front end portion 31 e of the female coupling housing 31compared to a direction from the front end portion 31 e to the rear endportion 31 d of the female coupling body 31.

According to one embodiment, a front sealing ring 35 is provided alongan inner circumferential surface 32 b of the sealing sleeve device 32 ata front end portion 32 e of the sealing sleeve device 32, wherein thefront sealing ring 35 comprises an inner diameter, wherein the innerdiameter is variable. According to one embodiment, the front sealingring 35 comprises a circumferential groove 35 a facing the rear endportion 31 d of the female coupling housing 31, wherein thecircumferential groove 35 a is configured to provide elasticity andenable the variation of the inner diameter of the outer sealing ring 35as well as providing a channel for hydraulic fluid which when filledwith pressurized hydraulic fluid reduces the inner diameter. Accordingto one embodiment, the effect of a reduced inner diameter corresponds toan increasing sealing force against a surface abutting or bearingagainst the front sealing ring 35, such as the outer surface 21 a of themale coupling body 21 when the male coupling body 21 has been insertedinto the female coupling body 31 as further described in connection toFIGS. 5 a-5 b . According to one embodiment, the circumferential groove35 a is v-shaped. According to one embodiment, the front sealing ring 35is configured to bear against the outer surface 21 b of the malecoupling body 21 with a higher force upon an increasing pressure of anhydraulic fluid within the female coupling housing 31 or alternatively,upon an increasing pressure within the combined housing of the femalecoupling housing 31 and the male coupling housing 21 when connectedtogether. According to one embodiment, the inner diameter is defined bya circumferential wedge-shaped portion 35 b. According to oneembodiment, the inner diameter is defined by a circumferential legportion 35 b 2 extending from a cylinder portion 35 c with an angletherebetween defined by the v-shaped circumferential groove 35 a.According to one embodiment, the circumferential leg portion 35 b2/wedge-shaped portion 35 b is shaped to provide a faster reduction ofthe inner diameter in a direction from the rear end portion 31 d to thefront end portion 31 e of the female coupling housing 31 compared to adirection from the front end portion 31 e to the rear end portion 31 dof the female coupling housing 31.

According to one embodiment, the rear sealing ring 34 is made ofpolyurethane, also known as PUR.

According to one embodiment, the front sealing ring 35 is made ofpolyurethane, also known as PUR.

FIG. 5 a shows a cross-section side view of a hydraulic coupling device10, comprising a male coupling unit 20 and a female coupling unit 30 ina closed position. The male coupling unit 20 has been introduced intothe female coupling part 30 whereby the male coupling body center axis21′ has been aligned with the female coupling body center axis 31′. Afront end portion 21 d of the male coupling body 21 abuts the sealingsleeve device 32, and the female poppet device 33 abuts the poppetdevice 24, without any pressure applied to overcome the spring forces ofspring device 36 and spring device 26 which thereby remain in anextended position. Hereby, the male coupling unit 20 and the femalecoupling unit 30 is in a closed position respectively, wherein nohydraulic fluid within the male coupling body 20 and/or the femalecoupling body 30 may exit their respective bodies or interiors throughopenings 21 f and 31 f respectively.

According to one embodiment, as seen in FIG. 5 a , the hydrauliccoupling device 10 further comprises a holding block 50, a guiding ring60, and an expanding ring 70 for fixedly arranging the female couplingunit 30 to the holding block 50. According to one embodiment, thehydraulic coupling device 10 comprises the female coupling unit 30, aholding block 50, a guiding ring 60, and an expanding ring 70 forfixedly arranging the female coupling unit 30 to the holding block 50.The female coupling body 31 is inserted from a female coupling bodyinsertion side 51 of the holding block 50, and the male coupling body 21is inserted from a male coupling body insertion side 52 of the holdingblock 50. According to one embodiment, the holding block 50 on the malecoupling body insertion side 52 comprises an opening 52 a of largerdiameter than the front end portion 31 e of the female coupling body 31.The opening 52 a comprises a cylindrical portion 52 c and a conicalportion 52 d with a decreasing diameter towards the female coupling bodyinsertion side 51, ending in a seat 53. According to one embodiment, thecylindrical portion 52 c of the opening 52 a comprises a thread surface52 c 1. According to one embodiment, the guiding ring 60 comprises anouter surface 60 a comprising a thread surface portion 60 a 1 configuredto engage with the thread surface portion 52 c 1 of the cylindricalportion 52 c of the opening 52 a. According to one embodiment, the frontend of the guiding ring 60 is provided with a plurality of openings 61 a1, 61 a 2, 61 a 3, 61 a 4, 61 a 5, 61 a 6 adapted to receive a toolcomprising corresponding pins to be inserted into the holes and engagewith the guiding ring 60 to enable a screwing motion of the guiding ring60. According to one embodiment, the openings 61 a 1, 61 a 2, 61 a 3, 61a 4, 61 a 5, 61 a 6 are circumferentially arranged on the front end ofthe guiding ring 60. According to one embodiment, the holes arecircular. According to one embodiment, the guiding ring 60 isessentially cylinder shaped, comprising a hollow core having an innerwall of varying diameter. A rear end of the guiding ring is adapted tobe inserted into the opening 52 a and face the female coupling bodyinsertion side 51. At the rear end of the guiding ring 60 the rear innerdiameter is initially larger than the diameter of the front end of thefemale coupling body 31. The space between the female coupling body 31and the inner wall of the guiding ring 60 forms a cylindrical guiding.The rear inner diameter decreases in a first step forming a cylindricalguiding seat, which according to one embodiment, may be conicallyshaped. The inner diameter then decreases in a second step forming asecond seat, essentially corresponding to the outer diameter of thefemale coupling body 31 and the male coupling body 21. According to oneembodiment, the expanding ring 70 has the shape of a part of a cone,wherein the rear end of the expanding ring 70 has a larger diameter thanthe front end of the expanding ring. The expanding ring 70 is configuredto be flexible and biased in a radially outward direction uponcompression radially inward. According to one embodiment the outersurface 31 a of the front end 31 e of the female coupling body 31comprises a circumferential groove 31 f configured to receive theexpanding ring 70. According to one embodiment, the circumferentialgroove 31 f provides the outer surface 31 a of the female coupling body31 the shape of a part of cone corresponding to the shape of theexpanding ring 70, wherein the diameter of the outer surface 31 a of thefemale coupling body 31 decreases towards the front end of the femalecoupling body 31. At the end of the groove 31 f, the diameter abruptlyincreases to form a groove seat 31 g for the expanding ring 70.

According to one embodiment, mounting of the hydraulic coupling device10 is carried out by first inserting the female coupling body 31 into inthe holding block 50 from the female coupling body insertion side 51.The expanding ring 70 is provided over the front end portion 31 e of thefemale coupling portion 31 by inserting the expanding ring 70 from themale coupling body insertion side 52 in the opening 52 a. Thereafter theguiding ring 60 is screwed into the opening 52 a, until contacting theexpanding ring 70 whereby the expanding ring 70 is pressed into the seat53 of the holding block by guidance of the conical portion of theopening 52 a. During further screwing of the guiding ring 60, theexpanding ring 70 is further guided by the cylindrical guiding to getfurther compressed and eventually engage with the circumferential groove31 f and the groove seat 31 g. Upon further screwing of the guiding ring60, the second seat of the guide ring 60 contacts or engages the frontend of the female coupling body 31 whereby the female coupling body ispressed in a rearward direction towards the female coupling bodyinsertion side 52, with the expanding ring 70 providing a support orholder-on or lock or stop for the female coupling body 31 preventing arelease of the female coupling body 31 in this direction towards thefemale coupling body insertion side 51.

FIG. 5 b shows a cross-section side view of a hydraulic coupling device10 in an open position. The male coupling unit 20 has been furtherintroduced into the female coupling unit 30 whereby the spring forces ofsprings 26 and 36 have been overcome compressing the springs 26, 36.During the entire movement from a closed to an open position, the poppetdevice 24 and the guide device 25 matingly engage each other, providinga guidance and preventing tilting of the parts. Further, in the openposition, a channel, or opening is created between the poppet device 24and in particular, the poppet sealing ring 28 and the inner surface 21 bof the male coupling body 21. Additionally a channel, or opening iscreated between the female poppet device 33 and the inner surface of thesealing sleeve device 32 and in particular the rear sealing ring 34. Asthe female poppet device 33 is inserted into the male coupling body 21in an open position, a channel, or opening is further provided betweenthe female poppet device 33 and the inner surface 21 b of the malecoupling body 21. The increasing diameter of the female poppet portion33 towards a front end portion 31 e of the female coupling body 31corresponds to an increasing diameter of the inner surface portion 21 bof the male coupling body 21 in a towards a rear end portion 21 d of themale coupling body 21. Hydraulic fluid within the male coupling body 21and/or the female coupling body 31 may exit their respective bodies orinteriors and enter the other of the male or female coupling body 21,31. The front sealing ring 35 provides a seal in the interface betweenthe male coupling body 21 and the female coupling body 31 preventingleakage of hydraulic fluid within the male coupling body 20 and/or thefemale coupling body 30.

A preferred embodiment of a male coupling unit 20, a female couplingunit 30, a hydraulic coupling device 10 according to the invention hasbeen described. However, the person skilled in the art realizes thatthis can be varied within the scope of the appended claims withoutdeparting from the inventive idea.

All the described alternative embodiments above or parts of anembodiment can be freely combined without departing from the inventiveidea as long as the combination is not contradictory.

The invention claimed is:
 1. A female coupling unit for a hydrauliccoupling device, comprising: a female coupling body comprising a hollowcore, wherein the female coupling body includes a rear end, a front end,and a sealing sleeve device, the sealing sleeve device is supported by aspring device and movable in relation to the female coupling bodybetween a closed and open position upon extension and compression of thespring device respectively, the female coupling unit further comprises afemale poppet device fixedly arranged to the rear end of the femalecoupling body in the hollow core and extending towards the front end ofthe female coupling body; a rear sealing ring is provided along an innercircumferential surface of the sealing sleeve device and adapted to bearagainst and slide along a front end portion of the female poppet deviceduring movement of the sealing sleeve device, and the rear sealing ringis configured to prevent flow of hydraulic fluid between the rearsealing ring and the female poppet device from the rear end of thefemale coupling body towards the front end of the female coupling bodyand permit flow of the hydraulic fluid between the rear sealing ring andthe female poppet device from the front end of the female coupling bodytowards the rear end of the female coupling body.
 2. The female couplingunit according to claim 1, wherein the rear sealing ring comprises aninner diameter, wherein the inner diameter is variable.
 3. The femalecoupling unit according to claim 2, wherein the rear sealing ringcomprises a circumferential groove facing the rear end of the femalecoupling body, and the circumferential groove is configured to provideelasticity and permit variation of the inner diameter.
 4. The femalecoupling unit according to claim 1, wherein a front sealing ring isprovided along an inner circumferential surface of the sealing sleevedevice at a front end of the sealing sleeve device, wherein the frontsealing ring comprises an inner diameter, wherein the inner diameter isvariable.
 5. The female coupling unit according to claim 4, wherein thefront sealing ring comprises a circumferential groove facing the rearend of the female coupling body, wherein the circumferential groove isconfigured to provide elasticity and permit variation of the innerdiameter.
 6. The female coupling unit according to claim 4, wherein thefront sealing ring is made of polyurethane.
 7. The female coupling unitaccording to claim 1, wherein the rear sealing ring is made ofpolyurethane.
 8. The hydraulic coupling device comprising: the femalecoupling unit according to claim 1, a holding block, a guiding ring, andan expanding ring for fixedly arranging the female coupling unit to theholding block in an opening of the holding block, wherein the guidingring comprises an outer surface comprising a thread surface portionconfigured to engage with a thread surface portion of a cylindricalportion of the opening of the holding block fixedly arranging theguiding ring to the holding block, a seat is provided in the opening forsupporting the expanding ring, an outer surface of the front end of thefemale coupling body comprises a circumferential groove comprising agroove seat, configured to receive the expanding ring, female couplingunit is adapted to be fixedly arranged to the holding block by beingsuspended between the guiding ring and the seat, and the expanding ringis arranged as a support between the female coupling unit and the seat.9. The hydraulic coupling device according to claim 8, furthercomprising a male coupling unit.
 10. The hydraulic coupling devicecomprising: the female coupling unit according to claim 1, and a malecoupling unit including a male coupling body including a hollow corehaving a male coupling body center axis extending in a male couplingbody extension direction, wherein the male coupling body comprises aninner surface, and a poppet valve device arranged in the hollow core,the poppet valve device comprises a poppet device, a guide device, and aspring device, a first end of the spring device is supported by thepoppet device and a second end of the spring device is supported by theguide device, the poppet device is movable in relation to the guidedevice along the male coupling body extension direction between an openand closed position upon compression and extension of the spring devicerespectively, the guide device is locked in the male coupling bodyextension direction, the inner surface comprises a thread surfaceportion, and the guide device comprises an outer surface comprising athread surface portion configured to engage with a corresponding threadsurface portion of the inner surface of the male coupling body forlocking the guide portion.
 11. The hydraulic coupling device accordingto claim 10, wherein the guide device includes a center portionextending in the male coupling body extension direction and a pluralityof legs extending in a direction from the male coupling body extensiondirection towards the thread surface portion, forming lead-throughchannels between the legs, and the thread surface portion is defined onthe outer ends of the legs.
 12. The hydraulic coupling device accordingto claim 10, further comprising a holding block, a guiding ring, anexpanding ring for fixedly arranging the female coupling unit to theholding block in an opening of the holding block, wherein the guidingring comprises an outer surface comprising a thread surface portionconfigured to engage with a thread surface portion of a cylindricalportion of the opening of the holding block fixedly arranging theguiding ring to the holding block, wherein a seat is provided in theopening of the holding block for supporting the expanding ring, whereinan outer surface of the front end portion of the female coupling bodycomprises a circumferential groove comprising a groove seat, configuredto receive the expanding ring, wherein the female coupling unit isadapted to be fixedly arranged to the holding block by being suspendedbetween the guiding ring and the seat, wherein the expanding ring isarranged as a support between the female coupling unit and the seat. 13.A hydraulic coupling device, comprising: a male coupling unit comprisinga male coupling body comprising a hollow core comprising a male couplingbody center axis extending in a male coupling body extension direction,wherein the male coupling body comprises an inner surface wherein themale coupling body further comprising a poppet valve device arranged inthe hollow core; a female coupling unit comprising a female couplingbody comprising a hollow core, wherein the female coupling bodycomprises a rear end, a front end, and a sealing sleeve device, whereinthe sealing sleeve device is supported by a spring device and is movablein relation to the female coupling body between a closed and an openposition upon extension and compression of the spring devicerespectively, and further comprises a female poppet device fixedlyarranged to the rear end of the female coupling body in the hollow coreand extending towards the front end of the female coupling body; aholding block; a guiding ring; and an expanding ring to fixedly arrangethe female coupling unit to the holding block in an opening of theholding block, wherein the poppet valve device comprises a poppetdevice, a guide device, and a spring device, a first end of the springdevice is supported by the poppet device and a second end of the springdevice is supported by the guide device, the poppet device is movable inrelation to the guide device along the male coupling body extensiondirection between an open and closed position upon compression andextension of the spring device respectively, the guide device is lockedin the male coupling body extension direction, the inner surfacecomprises a thread surface portion, the guide device comprises an outersurface comprising a thread surface portion configured to engage withthe corresponding thread surface portion of the inner surface of themale coupling body for locking the guide portion, the guiding ringcomprises an outer surface comprising a thread surface portionconfigured to engage with a thread surface portion of a cylindricalportion of an opening of the holding block fixedly arranging the guidingring to the holding block, a seat is provided in the opening of theholding block for supporting the expanding ring, an outer surface of thefront end portion of the female coupling body comprises acircumferential groove comprising a groove seat, configured to receivethe expanding ring, the female coupling unit is adapted to be fixedlyarranged to the holding block by being suspended between the guidingring and the seat, and the expanding ring is arranged as a supportbetween the female coupling unit and the seat.